Diffraction at the Open End of Dielectric-Lined Circular Waveguide

Radiation of a TM mode from an open end of a three-layer dielectric capillary

“…Sim-ilar to Refs. [17,18], an input end of the waveguide was supported by a series of numerical ports, one separate port for each propagating mode (the port that corresponds to the incident mode was set to be active). The corresponding eigenmodes were determined numerically, with analytically calculated longitudinal wavenumbers k zm being used as guess values.…”

“…( 3) transforms to the corresponding mode of a two-layer waveguide of radius d (Ref. [18]) for → ε. The problem is to find diffracted electromagnetic field both inside and outside the waveguide which satisfies ordinary boundary conditions on all boundaries and at the infinity together with the incident field (3).…”

“…[16] For further development of the discussed topics, a rigorous approach allowing the analytical study of both the radiation from such an open-ended capillary and its excitation by an external source (bunch or electromagnetic pulse) would be extremely useful. In our recent papers, [17,18] we presented an efficient rigorous method for solving circular open-ended waveguide diffraction problems and illustrated this method using the case of a uniform dielectric filling and a two-layer lining of the waveguide. Here we deal with a more complicated geometry offered in Ref.…”

“…(41) To obtain the Wiener-Hopf-Fock equation one should express the term Ψ This can be carried out using the continuity conditions for ρ = b, a, d, z > 0 (see Ref. [18] for details):…”

“…Similar to Refs. [17,18], the right-hand side of Eq. ( 42) formally possesses pole singularity for α = α m :…”